Pendulum-scale



(No Model.)

D. OLMSTED.

PENDULUM SCALE Patented Sept. 20

HHH

UNITED STATES PATENT OFFICE.

DAVID OLMSTED, OF MINNEAPOLIS, MINNESOTA.

PENDULUM-SCALE.

SPECIFICATION forming part of Letters Patent No. 482,831, dated September 20, 1892.

Application filed January 29,'l892. Serial No. 419,679. (No model.)

T0 on whom it may concern.-

Be it known that I, DAVID OLMSTED, a citi zen of the United States, residing at Minneapolis, in the county of Hennepin andState of Minnesota, have invented certain new and useful Improvemet in Automatic \Veighing Scales; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to automatic weighing-scales of the class generally known as pendulum-scales.

The object of my invention is to provide Weighing-scales which are simple in construction and accurate and automatic in operation, by means of which one may at once determine the weight of any article placed upon the platform without the necessity of ad justing any weights.

The matter constituting my invention will be defined in the claims. J

I will now describe the details of construction of my improved scales by reference to the accompanying drawings, in which- Figure 1 represents a front elevation with part of the annular dial-plate broken away. Fig. 2 represents a horizontal section through the casing, showing the mechanism of the scales in top plan view. Fig. 3 represents an elevation of a modified form of part of the mechanism.

I preferably provide a circular casing 1, having a solid back. An annular dial-plate 2 is secured near the front edge of the easing and inclosed at the front by a glass plate 3. A curved lever 4 is pivotally connected at one end by means of a pin or stud at, having a knife-edge to the bracket 5, secured to one side of the case 1, and is provided near its middle portion with a knife-edged stud or pin 1) and at its upper curved end with a pivotal knife-edged stud or pin 0, to which is pivotally connected the straight lever 6, having at or near its opposite end the weight 7, and resting in its normal condition near its weighted end upon the curved or arched fulcrum-beam 8. This fulcrumbeam 8 is provided at its opposite ends with flanges e and f, adapted to fit the curved wall of case 1, to which they are attached, so as to support the beam 8 transversely in the case, as shown, and said beam is preferably provided near its right-hand end with a downward offset g, so as to provide a recess for the weight '7, as shown in Fig. 1. At about the middle of beam 8 there is secured to its front side a bracket 9 for supporting shaft 14; and its connections. The straight lever 6 is provided at its free end with ashort arm (Z, projecting forward at right angles to the lever and having attached to its outer end a cord 10, which passes over a pulley 11 just below arm (I, and thence over the spirally-grooved cone-pulley 12, fixed on shaft 14: in bracket 9, and has attached to its free end the weight 13.

To the front end of shaft 11 is fixed the index-finger 16, extending radially outward' over the annular dial-plate 2, as shown in Fig. 2. The pulley 11 is supported on a stud or pin in a bracket 15, secured to the wall of the casing near the end of curved beam 8. Instead of pulley 11 I may employ at this point simply a pin or stud as a guide over which cord 10 is passed to the cone pulley.

By means of the cord and weight passing over grooved pulley 12 the motion of lever 6 is steadied and made more uniform, and at the same time shaft 14 and the pointer or index-finger 16 are given a positive motion and without the vibration and lost motion which occur when a rack and pinion are employed for moving the pointer. By means of the spirally-grooved cone-pulley variations in the spacing of the scale upon the annular dialplate are compensated for, so as to secure greater accuracy in indicating the weight of various articles placed upon the scale.

Upon the knife-edge stud b on lever 4 is hung the hook 18, to which is connected rod 20, connecting atits lower end with the plat form. (Not here shown.)

Instead of making the straight lever 6 and the curved fulcrum-beam 8 with plain bearing-surfaces, as shown in Fig. 1, they may be notched and pointed, as shown in Fig. 3, in which the curved beam 8 is provided with a series of evenly-spaced notches and in which the straight lever 6 is provided with a corresponding series of evenly-spaced points or teeth fitting into the notches, as shown; but my invention is not confined to this construction.

As will be seen from the above description and the accompanying drawings, very few parts are used in my automatic weighingscales and the arrangement of parts is very simple and effective. It will be understood that as the weight is increased upon the scaleplatt'orm the lever "12 will be pulled down, carrying with it the straight leverG, and the fulcrum on curved beam 8 will be shifted from right to left, so that the weight 7 and the free end of lever 6 will exert a progressively-increasing leverage in proportion to the weight of the article upon the scale-platform. The scale being balanced, as shown in Fig. 1, and the article to be weighed being placed upon the platform, the levers 4 and 6 will be depressed, and on account of the fulcrumpoint being progressively changed or shifted to the left the weight 7 will act with increasing resistance until the article is balanced. As the free end of lever 6 is raised the cord 10 is drawn over pulley 11 and the grooved cone-pulley 12, turning such pulley and the shaft to which it is attached, and thereby traversing the index-1inger16 over the annular dial-plate 2, where the weight of the article is indicated. This movement of the index-finger is effected without any oscillation or vibration, since by means of the weighted cord. and grooved pulley there is no lost motion between the parts, and the weight of the article is more accurately and quickly ascertained.

In actual practice it is found that as the weight grows heavier upon the platform the indications upon the dial grow smaller. This is illustrated in the makingof dials for steamgages. Each dial is marked separately and a division of the inequalities made to make them look uniform. This will not do for accurate weighing, and hence the introduction of the cone-pulley. According to its shape or formation the needle or pointer may be governed in its action to gain or lose, as desired.

Having now described my invention, what I claim, and desire to secure by Letters Patent, is-

1. The lever 4, provided near its middle portion with a stud b and pivoted at one end to a fixed support and having the other end curved upward, and the straight lever 6, pivotally connected to such curved end of lever 4 and having at or near its free end a weight, in combination with the curved fulcrum-beam 8, fixed transversely in the casing, an indexfinger and means for operating it connecting with lever 6, and the platform-rod hung upon stud b, substantially as described.

2. The curved lever l and the weighted straight lever 6, pivotally connected, as described, in combination with the curved fulcrum-beam 8, supporting-lever 6, said beam having supported thereon a shaft carrying a pulley and index-finger, a guide adjacent to the end of said beam, a cord attached to the end of lever (3 and passing over said guide and pulley, and a weight attached to the free end of the cord, substantially as described.

3. The curved lever i and weighted straight lever 6, pivotally connected, as described, in combination with the eu rved f ulcrum-beam 8, the shaft 14-, carrying grooved cone-pulley 12, and index-finger 16, supported on said beam 8, pulley 11, and a cord 10, attached to the end of lever O, passing over pulleys 11 and 12 and having a weight attached to its free end, substantially as described.

4:. In combination with lever 6, fulcrumed upon the curved beam 8, a suitably-supported rotary shaft carrying a cone-pulley and indexfinger, a guide near the end of beam 8, and the weighted cord attached to the free end oflever 6 and passing over said guide and pulley, substantially as described.

In testimony whereof I affix mysignature in presence of two witnesses.

DAVID OLMSTED. Witnesses:

JOHN W. Coma, EDsoN S. GAYLoRn. 

